Dr. Jenny Zenobio, Ph.D.

Tracking PFAS Transport and Deposition Through Rainwater

Dr. Jenny Zenobio, Ph.D., Environmental Chemist and Ecotoxicologist, Jacobs 

Per- and polyfluoroalkyl substances (PFAS) are persistent and globally distributed chemicals resulting from their extensive use in industrial processes, firefighting foams, and consumer products such as non-stick cookware, waterproof textiles, and food packaging. Due to their chemical stability and mobility, PFAS are transported through the atmosphere and deposited via rainwater, facilitating their transfer to soil, surface water, and groundwater. This study examines PFAS behavior in rainwater, highlighting their sources, transport mechanisms, deposition patterns, and environmental implications.  PFAS in rainwater arises from a combination of local emissions, long-range atmospheric transport, and precipitation dynamics. Elevated concentrations of legacy PFAS (e.g., PFOA, PFOS) and increasing levels of short-chain PFAS (e.g., TFA, PFBA) reflect a shift in usage patterns, PFAS transport, and precursor transformations. Trifluoroacetic acid (TFA), in particular, has shown significant increases over the past two decades, underscoring its persistence and global reach. Geographic trends indicate that urban and industrial areas experience higher PFAS concentrations due to localized emissions, while measurable background levels in remote regions highlight the role of long-range transport.  Precipitation type significantly influences PFAS deposition. Convective rainfall events, characterized by strong updrafts, entrain local PFAS emissions and produce higher concentrations, whereas stratiform events primarily reflect broader regional or long-range contributions. Seasonal variability further impacts PFAS profiles, with increased concentrations of short-chain PFAS during summer months, likely driven by enhanced atmospheric activity and transport dynamics. Additionally, in urban settings, surface runoff from impervious surfaces can contribute more significantly to nearby water bodies than direct atmospheric deposition, emphasizing the need to consider multiple pathways of PFAS loading.  This synthesis of recent research highlights the complex interplay of PFAS sources, transport mechanisms, and deposition processes in rainwater. Understanding these dynamics provides critical insights into PFAS environmental cycling, enabling more effective monitoring, source attribution, and mitigation strategies to address their widespread presence and impacts on ecosystems and human health.

Dr. Jenny Zenobio is an environmental chemist and ecotoxicologist specializing in the fate, transport, and remediation of emerging contaminants, focusing on PFAS and microplastics. With a PhD in Environmental Chemistry from Purdue University, her expertise combines engineering, toxicology, and chemistry to tackle complex water pollution challenges. At Jacobs, she leads PFAS investigations, contributes to research projects with WRF and SERDP/ESTCP programs, and advances innovative remediation strategies, including passive sampling validation, PFAS fingerprinting for forensic investigations, and treatability studies. Dr. Zenobio has published extensively, holds a U.S. patent for PFAS degradation technologies, and has significantly contributed to understanding PFAS-microplastic interactions. Her work bridges cutting-edge research and practical applications, driving advancements in environmental protection and sustainable contaminant management.